2tmv

Caspar Carboxylates
Two clusters of acidic amino acids are thought to be important for the disassembly of the helical structure of TMV. When the virus enters cells, the higher pH and lower calcium levels increase the repulsion of neighboring carboxylates, destabilizing the capsid. This concept was originally proposed by Caspar and subsequently examined by site-directed mutagenesis. Several carboxylates were identified including Glu50 and ASP77, which contact each other in the helical stack (look closely at the two subunits that overlap in this lockwasher complex), and a cluster of four acidic amino acids, GLU95, GLU97, GLU106 and GLU109 , near the center of the ring.

This section complements the article on Tobacco Mosaic Virus in the Molecule of the Month Series. See also Teaching Scenes, Tutorials, and Educators' Pages.

About this Structure
2TMV is a 2 chains structure with sequences from Tobacco mosaic virus. The January 2009 RCSB PDB Molecule of the Month feature on Tobacco Mosaic Virus by David Goodsell is 10.2210/rcsb_pdb/mom_2009_1. Full crystallographic information is available from OCA.